Technical Field
This disclosure relates to a sheet feeder and an image forming apparatus incorporating the sheet feeder.
Related Art
Various types of known image forming apparatuses include a sheet feeder having a multi-feed sheet separator. Such a multi-feed sheet separator includes a sheet feed roller that functions as a sheet feed unit, a pickup roller, a sheet separation roller that functions as a sheet separating unit, a brake, a separation roller holder, a pressure spring, and a separator. A sheet that functions as a recording medium has a leading end that bends between the pickup roller and the sheet feed roller due to a reaction force generated by contacting a nip region formed between the sheet feed roller and the sheet separation roller or the separator, which increases a degree of a contact angle with the separator. The increase in the contact angle decreases a shearing force that can be applied by the separator to flip through the multi-feed sheets, and therefore the multi-feed sheet separator cannot separate the sheets. As a result, the multi-feed errors occur frequently. As an example, a configuration having a sheet guide on an opposite side to the separator has been proposed to address this inconvenience.